NITROGEN, PHOSPHORUS, AND POTASSIUM FERTILITY REGIMES AFFECT TOMATO TRANSPLANT GROWTH

Tomato (Lycopersicon esculentum Mill.) seedlings were nutritionally conditioned with solutions containing factorial combinations of N at 25, 75, and 225 mg.liter-1, P at 5, 15, and 45 mg.liter-1, and K at 25, 75, and 225 mg.liter-1 to determine the effect of nutritional regimes on tomato transplant growth and quality. As N increased from 25 to 225 mg.liter-1, fresh shoot weight, plant height, stem diameter, leaf number, leaf area, shoot and root dry weights, and total chlorophyll increased. Nitrogen accounted for the major source of variation. Phosphorus effects were significant only in 1988; P at 45 mg.liter-1 increased fresh shoot weight, plant height, stem diameter, leaf number, and leaf area in comparison to 5 and 15 mg.liter-1. Potassium did not significantly influence any of the growth variables measured in the study. For quality transplant production, nutrient solutions should contain at least N at 225 mg.liter-1, P at 45 mg.liter-1, and K at 25 mg.liter-1.